花椰菜中器官早期发育调控相关的miRNA(Bra-miR07)的克隆及功能研究

在前期通过高通量小RNA测序获得若干在花椰菜器官早期发育过程中呈现差异表达的未知功能miRNA基础上,重点对其中1个在花椰菜下胚轴和子叶中表现为显著差异表达的miRNA(命名为Bra-miR07)进行克隆鉴定及功能分析。研究表明,Bra-miR07前体序列全长为270 bp,可形成稳定的二级发夹结构。Bra-miR07在花椰菜子叶中呈现显著高表达。进一步构建了Bra-miR07的过表达载体并采用浸花法转化拟南芥,获得Bra-miR07过表达的转基因拟南芥株系。表型分析显示,Bra-miR07过表达可显著影响拟南芥植株生长。与野生型相比,过表达Bra-miR07株系表现为生长缓慢,植株矮小,育性降低等发育受阻特征。因此,上述结果预示着Bra-miR07可能也在花椰菜器官发育过程中发挥重要作用。

Cloning and Functional Analysis of a miRNA (Bra-miR07) Associated with the Regulation of Early Organ Development in Cauliflower

In the previous study，a series of novel miRNAs that show significantly different expression in the early organ development of cauliflower were obtained by high-throughput sequencing. In the present study，a novel miRNA that showed different expression between cauliflower hypocotyl and cotyledon was named Bra-miR07 and further analyzed. The results indicated that the sequence length of Bra-miR07 precursor was 270 bp which can form the stable secondary hairpin structure. Bra-miR07 appeared higher expression in cauliflower cotyledon than that in hypocotyl. To further uncover the function of Bra-miR07，overexpression vector of Bra-miR07 was constructed and transferred into Arabidopsis thaliana by floral dip，and the Bra-miR07 overexpression transgenic plants were successfully obtained. Phenotypic analyses showed that overexpression of Bra-miR07 can significantly influence thegrowth and development of transgenic plants. Compared with wild-type Arabidopsis，Bra-miR07 transgenic plants showed slow growth，dwarf plant and lower fertility. Consequently，these results implied that Bra-miR07 may also play important roles in regulation of cauliflower organ development.